xen/privcmd: Fix mmap batch ioctl error status copy back.

Copy back of per-slot error codes is only necessary for V2. V1 does not provide
an error array, so copyback will unconditionally set the global rc to EFAULT.
Only copyback for V2.

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 92a285b..3b162c6 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -389,7 +389,7 @@
 		state.err      = err_array;
 		ret = traverse_pages(m.num, sizeof(xen_pfn_t),
 				     &pagelist, mmap_return_errors_v1, &state);
-	} else
+	} else if (version == 2)
 		ret = __copy_to_user(m.err, err_array, m.num * sizeof(int));
 
 	/* If we have not had any EFAULT-like global errors then set the global